> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sdf.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Datetime Functions

## `current_datetime`

*Supported Signatures*

```sql theme={null}
function current_datetime() returns datetime
function current_datetime(string) returns datetime
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#current_datetime)

## `datetime`

*Supported Signatures*

```sql theme={null}
function datetime(bigint, bigint, bigint, bigint, bigint, bigint) returns datetime
function datetime(date) returns datetime
function datetime(date, time) returns datetime
function datetime(timestamp) returns datetime
function datetime(timestamp, string) returns datetime
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#datetime)

## `datetime_add`

*Supported Signatures*

```sql theme={null}
function datetime_add $1($1, interval) returns $1
	where $1 in (date, timestamp)
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#datetime_add)

## `datetime_diff`

*Supported Signatures*

```sql theme={null}
function datetime_diff $1($1, $1, part string) returns bigint
	where part in (microsecond, millisecond, second, minute, hour, day, week, week(monday), week(tuesday), week(wednesday), week(thursday), week(friday), week(saturday), week(sunday), isoweek, month, quarter, year, isoyear)
	where $1 in (date, timestamp)
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#datetime_diff)

## `datetime_sub`

*Supported Signatures*

```sql theme={null}
function datetime_sub $1($1, interval) returns $1
	where $1 in (date, timestamp)
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#datetime_sub)

## `datetime_trunc`

*Supported Signatures*

```sql theme={null}
function datetime_trunc $1($1, date_time_part string) returns $1
	where date_time_part in (microsecond, millisecond, second, minute, hour, day, week, week(monday), week(tuesday), week(wednesday), week(thursday), week(friday), week(saturday), week(sunday), isoweek, month, quarter, year, isoyear)
	where $1 in (date, timestamp)
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#datetime_trunc)

## `format_datetime`

*Supported Signatures*

```sql theme={null}
function format_datetime $1(string, $1) returns string
	where $1 in (date, timestamp)
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#format_datetime)

## `parse_datetime`

*Supported Signatures*

```sql theme={null}
function parse_datetime(string, string) returns datetime
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#parse_datetime)